P1247: IDENTIFICATION AND VERIFICATION OF IMMUNE-RELATED GENE PROGNOSTIC SIGNATURE BASED ON SSGSEA FOR DLBCL
Authors: Wenyu Shi
Journal: HemaSphere (2023)

Topic: 20. Lymphoma Biology & Translational Research Background: Diffuse large B-cell lymphoma (DLBCL) is the most common type of adult lymphoma and is highly heterogeneous in terms of clinical presentation and prognosis. The tumor microenvironment (TME) and effective immune surveillance play important roles in the pathogenesis of diffuse large B-cell lymphoma (DLBCL) and are closely related to prognosis. Aims: This study aimed to evaluate immune cell infiltration and identify genetic features associated with patient survival. Methods: We analyzed RNA sequencing data from 223 DLBCL patients downloaded from GEO using ssGSEA and performed differential gene analysis between high and low immune groups. Duplicated genes were identified using a Venn diagram, and genes associated with poor prognosis were identified using COX and LASSO regression. Four genes (CELF2, KIFC1, MEGF6, S100A9) were used to construct a prognostic model and validated using GSE10846 and GSE87371 datasets. KIFC1 was further analyzed for its clinical and prognostic significance. WB detected the expression of KIFC1 in lymphoma cell lines such as OCI-LY8, 10, 18, 19 and TMD8, and selected two cells for experiments. After using KIFC1 inhibitor AZ82, the viability, proliferation, apoptosis, and cycle changes of tumor cells were detected, and the molecular mechanism of KIFC1 was explored. The tissues of 109 DLBCL patients were collected for multiplex immunofluorescence to detect the relationship between the expression level of KIFC1 and immune cells in the tumor microenvironment Results: We identified 22 duplicated genes, including KIFC1, which was significantly associated with poor patient prognosis. The prognostic model constructed using the four identified genes accurately predicted patient survival and was validated using independent datasets. KIFC1 was differentially expressed in high and low immune groups, positively correlated with patient risk scores, and associated with clinical parameters such as extra-nodal involvement, ECOG grade, and tumor subtype. KIFC1 expression was significantly higher in tumor tissues than in normal tissues and was identified as an independent prognostic factor. WB confirmed that KIFC1 was commonly expressed in DLBCL cell lines, and KIFC1 inhibitor AZ82 significantly reduced the viability and proliferative ability of lymphoma cells, inducing tumor cell apoptosis and G1 phase arrest. Further studies found that KIFC1 activates ATM-CHK2-P53-P21/P27 through DNA damage response, inhibiting cells from entering the S phase. The results of tissue multiplex immunofluorescence showed that when KIFC1 was highly expressed, CD8+ T cells were significantly reduced, and neutrophils and M2 macrophages infiltrated were increased. Clinicopathological correlation analysis showed that KIFC1 expression was correlated with IPI score and lactate level, and patients with high KIFC1 expression had a worse prognosis. Summary/Conclusion: Our study provides a novel approach to predicting the prognosis and survival of DLBCL patients using genetic features. The results showed that high expression of KIFC1 was closely related to poor prognosis in clinical patients. Functionally, KIFC1 inhibitor AZ82 can effectively inhibit the proliferation and viability of lymphoma cells, induce DNA damage and apoptosis. These results suggest that KIFC1 is a potential therapeutic target. Keywords: B cell lymphoma